org.apache.openjpa.conf.CacheMarshaller Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
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* KIND, either express or implied. See the License for the
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*/
package org.apache.openjpa.conf;
import org.apache.openjpa.lib.conf.Configurable;
import org.apache.openjpa.lib.conf.Configuration;
/**
* Responsible for marshalling and unmarshalling objects between memory and
* durable cache.
*
* @since 1.1.0
*/
public interface CacheMarshaller {
/**
* Load and return an instance of the type handled by this marshaller.
* If the type implements {@link Configurable}, then this method will invoke
* {@link Configurable#setConfiguration},
* {@link Configurable#startConfiguration()}, and
* {@link Configurable#endConfiguration()} on the instance before returning.
*/
Object load();
/**
* Store o into the cache.
*/
void store(Object o);
/**
* The id that this marshaller is responsible for.
* A value for this parameter is required.
*/
void setId(String id);
/**
* The id that this marshaller is responsible for.
*/
String getId();
/**
* The {@link ValidationPolicy} that this marshaller should use.
* A value for this parameter is required. The class will be instantiated
* via the {@link org.apache.openjpa.lib.conf.Configurations} mechanism,
* ensuring that if the class implements {@link Configurable} or
* {@link org.apache.openjpa.lib.conf.GenericConfigurable}, it will be taken
* through the appropriate lifecycle.
*/
void setValidationPolicy(String policy)
throws InstantiationException, IllegalAccessException;
/**
* Validation policies are responsible for computing whether or not a
* cached data structure is valid for the current context.
*
* getValidCachedData(getCacheableData(o), conf) should
* return an object equivalent to o in the expected case.
*
* Implementations of this class will often also implement
* {@link Configurable} in order to receive the current
* {@link Configuration}.
*/
public interface ValidationPolicy {
/**
* Returns an object that this policy considers to be valid, based
* on o. If o is not valid, this method
* will return null.
*/
Object getValidData(Object o);
/**
* Return an object that the {@link CacheMarshaller} should store.
*/
Object getCacheableData(Object o);
}
}